There are different values and settings that can be customised within a Just In Mac H.264 Capture Preset. Initially, the container type can be selected. There are two container options available:
AVFoundation QuickTime (with Timecode Track)
MP4 (no Timecode Track)
H.264 is a complex codec standard and is a bit more tedious to set up. Therefore, Just In Mac provides various options, which can be modified within an “H.264 preset”. After choosing the container type, you have to define two general settings:
After choosing the container type, you have to define two general settings:
Resolution
Frame rate (has to match the Video Mode of the Channel)
Next, you need to select the H.264 profile. Three options are available:
“Baseline” - Baseline encodes are the most basic form of encoding. While decoding is much easier, it may also require much higher bit rates to maintain the same level of quality.
“Main” - The middle ground. Most modern/current devices will support this profile.
“High Profile” - For best quality and file size at the expense of CPU time in both decoding and encoding.
Then you can set the Bitrate in bit/s.
B-Frame - Short for bidirectional frame, or bidirectional predictive frame. As the name suggests, B-frames rely on the frames preceding and following them. B-frames contain only the data that has changed from the preceding frame or is different from the data in the very next frame. B-frames increase compression efficiency, particularly at lower bitrates. We recommend having this option enabled.
The GOP-Size determines the maximum distance between I-frames. Very high GOP lengths will result in a slightly more efficient compression but will make seeking/scratching in the video somewhat more difficult. The recommended default is 0, which sets the encoder to Auto-GOP.
Lastly, you can define the Entropy Mode. When you select the “Main “or “High Profile” (“Baseline” is “CAVLC” only), you have two options:
“CAVLC”: Context-based adaptive variable-length coding
“CABAC”: Context-based adaptive binary arithmetic coding
“CAVLC” is the lower-quality, easier-to-decode option, “CABAC” is the higher-quality, harder-to-decode option.
Recommended settings for HD presets:
Resolution: custom
Frame rate: custom
Profile: “Main” or “High”
Bitrate: custom
Allow B-Frames: Activated
GOP-Size: “0”
Entropy Mode: “CABAC”
Recommended settings for SD presets:
Resolution: custom
Frame rate: custom
Profile: “Baseline” or “Main”
Bitrate: custom
Allow B-Frames: Activated
GOP-Size: “0”
Entropy Mode: “CAVLC”